Circular knife for woodcutting machines



Jan. 13, 1931. ECKERSLEY 1,788,456

CIRCULAR KNIFE FOP WOODCUTTING MACHINES Filed Oct. 30, 1929 2 Sheets-Sheet 1 Jan. 13, 1931. J. E. ECKERSLEY 1383,4555

CIRCULAR KNIFE FOR WOODCUTTING MACHINES Filed 001;. 50, 1.929 2 Sheets-Shat 2 .Patente cl Jan. 13,1931] f ur-ursn STATES JAMES E. ncxnnsnnir, or ABERDEEN, wrsmmmngissmrse osiomgn m no I ALEXANDER POLSON, or noourAivr,;-wnsn rneron Y CIRCULAR KNIFE FOR WoonouTTine'MAcHInEs Application filed OctoberZO, 1 9 2 9. Se rial No. 403,573.

Knives used in shingle and veneer machines are subjected to tremendous strains,

stresses and tension, due to heat resulting from friction in the material operated upon during the course of the cutting operation.

In such knives built up n sol d form, tne

rim or cutting dege has a tendency to wobble,

or snake, thereby. causing the cutting of the stock in uneven thickness, which results in a lossto the manufacturer, because such uneven shingles or veneer must be classed as portion of each segment-during its cutting action. r A further object of my invention 1s to provide means to interlock the abutting side edges of adjacent segments flush; and with these and other objects in view my invention consists of the parts and comblnation of parts hereinafter pointed out.

In the drawings Figure 1 is a top-plan View of a circular knife embodying my invention. 7

Figure 2 is an enlarged detail view of assembled segments of the knife. v

Figure 3 is a front edge elevationof one of the segment knives.

Figure 4: is a detail top plan view of assembled segments. 7

Figures 5 to 11 are detail views of different means which may be used in assembling the segments to form the circular knife. Figure 12 is a'detail sectional view. The reference numeral 14 designates the base ring or plate of the knife which-may be of any approved construction and desired s1ze. 1

The segments 15 may be'of any desired size and number to fit the base ring 14 selected. These segments or knives are'made in the shape of a segment and are provided with cutting edges 16 from which edge the knives are bevelled on their underside back to the point 17 (shown in dotted lines in Figures 1 5' and At the outer corners the segments are bevel ground to the-edgc, the inner margm of the bevel being designated by the numeral 18,;and these corners are bevelled or cut away as zit-19; The obje'ct'of thesecut away" or rounded corners 19 is to prevent slivers from accumulating betwcenthe abutting edges of ad acent knife-segments.

On the top side of eachsegmcntzlo I form grooves 20 which extend substantially from' I the dotted line17 towards the cutting edge 16, but'stopping short of such edge. In the cuttlng action the cutting edge zone of a knife becomes heated; I eliminate this heating by placing water, or other cooling medium on.

the segments and by centrifugal action the Water is thrown outward until it enters the grooves 20 through which the cooling medium is distributed on the segment near its cutting edge and prevents undue heating of such edge. I

The segments are secured to the plate '14 by means of screws 21, or other suitable n means, the heads of which are countersunk in the segments. I 1 In order to keep the abut-ting edges of adj acent segments flush and in the same plane I have adapted a number of cxpedients, some of which are shown in Figures 5 to 11.

In Figure 5 the edge of one of the segn'ients is concaved as at 22 which the abutting edge of the adjacent segment is concaved as at 23,

forming in effect a tongueand groove joint.

In Figures 6 and 8 the construction is a tongue and groove joint of different configuration.

' In Figure 7 the abutting edges of adjacent segments are concaved as at 24 and a round key 25 is seated in said concaves 24;

Figure 9 shows 1n effect the same construction as is shown in Figure 7 except that the joint is angular.

In Figure 10 the abutting edges of adjacent sections are each provided with a groove knife segments flush and in the same plane, and in the plane of the body of the segment.

I am aware that changes may be made in my improved circular knife ithout departing from the scope of theappended claims. \lVhatI claim is: I J 11" 1. In a circular knife, 21 circularignife hay, a plurality of knife segmentsseciifed to said bar side'by side, the oii'ter'corne'ts ofsaid knife segments converging towaird cent-m1 radial line. i

2. In a .knife a knife hfid h i viiig' grooi es in its upper face designedte conduct a cool 111g medium toward theciitting edge pi ltio'n.

- I 3-3.- In n f k' ifebladehaving gro ve V :in its upper: face terminating at; their outer. ends short oft-he cutting-edge of the blade. g4. ,In ,a circnl ai knife, aoircula-r knife bar,

a. p ura ity of 'knifesegmentsse ured tqsaid bmi ide bya de, growesin .theiupper; faces of said segmentstei minating short offthe cutting edge zone thereof and designed to supply a cooling medium to said; zone. Q

In testimonywhereof I affix my-sign'zitiii'e. JAMES E. ECKERSLEY. 

